Biosensor could monitor glucose levels in tears and sweat

A thin, flexible sensor has been developed with a view to help diabetics, researchers have reported in the journal, ACS Nano. The biosensor aims to track glucose levels through tears and sweat and could be incorporated into contact lenses or watches for real-time monitoring.

Previous challenges with wearable glucose trackers reside in the ability to detect the low levels of glucose that are in sweat and tears or breakage occurring when the device is bent. Moh Amer, Chongwu Zhou and colleagues have begun their research to overcome these issues.

Using nanoribbons of indium oxide, an enzyme glucose oxidase, a natural chitosan film and single-walled carbon nanotubes, the researchers created a biosensor. When glucose is present in a test sample, it interacts with the enzyme, setting off a short chain of reactions and creating an electrical signal.

Testing apparently showed that the device could detect a range of glucose concentrations from 10 nanomolar to 1 millimolar. According to the team, this is sensitive enough to cover typical glucose levels in sweat, saliva and tears in people with and without diabetes.

The team also bent the film 100 times during testing, reporting back that the device performance was not noticeably affected.

The researchers say that future development for the sensor may lie within food and environmental monitoring.